The facility, which includes two hydraulic cranes and mooring pontoons, will measure 85 metres by 15 metres and will accommodate ships up to 10,000 tonnes.

It can be used in winds of up to Force Six. Once it is operational, by the middle of next year, the old jetty will be demolished.

Portsmouth Naval Base Commander, Commodore Rob Thompson, got the construction underway by pressing a button to start the 'driving-in' of the first main jetty piles.

He said:

"This project has been planned for a long while so it is tremendous news that work has now started. It will be of great benefit to the naval base and the Navy as a whole - it will be used not only by the new Type 45s, but also our Type 42 destroyers, Type 23 frigates and other surface vessels."

Gerrit Smit, project manager at VolkerStevin Marine, which is building the facility, said:

"We are delighted to be involved in this prestigious project which is so important for the Royal Navy. It is the first time we have worked with the Ministry of Defence but I hope this is the start of a lasting relationship."

Paul Simmonds of the Defence Infrastructure Organisation (DIO), who is managing the project, added:

"The DIO is delighted to see the first piles driven. VolkerStevin Marine is to be congratulated for its professionalism in the way it has managed to mobilise, progress the design and start construction before the closed season for piling operations in Portsmouth Harbour.

"We look forward to a successful programme and the delivery of a facility that will support our ships for many years to come."